The present invention generally relates to an ultrasound system and in particular to an ultrasound diagnostic system that instructs at least one processor to perform parallel arithmetic or logic instructions upon multiple ultrasound data points simultaneously during one clock cycle.
Ultrasound systems have been used for many years in the field of radiology by physicians to examine various areas of humans, such as the heart, a fetus, arteries, organs and the like. Ultrasound systems typically include two primary subsystems, a front end subsystem and a back end subsystem. The front end subsystem includes one or more ultrasound probes for scanning an area of interest within a patient. Conventional front end subsystems also include a beamformer hardware unit that enables transmission of ultrasound signals into the patient and acquires ultrasound echo signals therefrom. The front end subsystem passes acquired echo signals to the back end subsystem which performs signal processing upon the acquired echo signals. The back end subsystem converts the processed echo signals to a format displayable on a CRT and displays the echo signals in a desired format, such as a graph, a two-dimensional image, a three-dimensional image, a black and white image of anatomic structure (B-mode image), a colorized image of moving tissue or moving fluid, and the like.
In the past, the front and back end sections of ultrasound systems were constructed in a hardware intensive manner utilizing multiple hardware boards, each board of which performed predetermined dedicated ultrasound operations. In past ultrasound systems, dedicated hardware boards were included to perform signal processing and separate dedicated hardware boards were provided to perform scan conversion. Scan conversion includes the task of translating the incoming data from a beam coordinate space, usually polar, to Cartesian coordinate space. In addition, past ultrasound systems required a separate central processor to control the various dedicated hardware boards. The central processor did not perform signal processing or scan conversion operations. Instead, the central processor primarily performed system control operations, such as setup to configure the hardware boards when the system was first turned on and management of the dedicated hardware boards throughout operation.
Ultrasound systems have been proposed which utilize digital signal processors (DSP) to carry out signal processing and scan conversion. One or more DSPs cooperate to perform signal processing. The DSPs dedicated to signal processing are housed as a set on one or more printed circuit boards. A separate set of DSPs housed on a separate set of printed circuit boards are programmed to perform scan conversion. However, even in systems using DSPs, each set of DSPs is dedicated to specific processing operations. Hence, a DSP configured to perform Doppler signal processing cannot perform scan conversion. In addition, ultrasound systems which utilize DSPs continue to require a separate central CPU to maintain system control.
More recently, in the early 1990s, the assignee of the present application introduced ultrasound systems based on the architecture of a personal computer (PC). These ultrasound systems were referred to under the trademarks and tradenames, ESI5000.TM. and Synergy.TM.. The ESI5000.TM. and Synergy.TM. ultrasound systems included DSP boards for signal processing and a central processor for controlling overall operation of the ultrasound system. The central processor of the PC was used to carry out setup operations and to control the DSP boards. The central CPU in the Synergy.TM. system also performed scan conversion of Color Doppler images from polar coordinates to Cartesian coordinates. Also, the ESI5000.TM. and Synergy.TM. systems utilized a front end subsystem having separate beamformer hardware.
However, conventional ultrasound systems have experienced limitations. In particular, conventional ultrasound systems require individual processors or DSPs to process data sequentially. For example, in a conventional ultrasound system, a processor or DSP may be dedicated to perform scan conversion operations. The dedicated processor or DSP receives a sequence of data samples associated with a scan of the patient. The dedicated processor or CPU performs a sequence of arithmetic operations to convert the ultrasound data samples from a polar coordinate system (as utilized when scanning a patient) to a Cartesian coordinate system (as utilized to display image information). In the past, the dedicated processor or CPU performed the arithmetic operations necessary for scan conversion in a sequential fashion. Sequential processing of the data samples reduces the systems operating speed and creates "bottle necks" within the overall ultrasound processing sequence. Consequently, sequential processing has resulted in a limitation upon the performance of conventional ultrasound systems.
A need remains for an improved ultrasound system to overcome the above-identified difficulties. It is an object of the present invention to meet this need.